udev: silence notification failures (#40275)

Closes #39943.

src/shared/daemon-util.c

@@ -9,7 +9,7 @@
 #include "string-util.h"
 #include "time-util.h"
 
-int notify_remove_fd_warn(const char *name) {
+static int notify_remove_fd_full(int log_level, const char *name) {
         int r;
 
         assert(name);
@@ -18,13 +18,22 @@ int notify_remove_fd_warn(const char *name) {
                        "FDSTOREREMOVE=1\n"
                        "FDNAME=%s", name);
         if (r < 0)
-                return log_warning_errno(r,
-                                         "Failed to remove file descriptor \"%s\" from the store, ignoring: %m",
-                                         name);
+                return log_full_errno(
+                                log_level, r,
+                                "Failed to remove file descriptor \"%s\" from the store, ignoring: %m",
+                                name);
 
         return 0;
 }
 
+int notify_remove_fd(const char *name) {
+        return notify_remove_fd_full(LOG_DEBUG, name);
+}
+
+int notify_remove_fd_warn(const char *name) {
+        return notify_remove_fd_full(LOG_WARNING, name);
+}
+
 int notify_remove_fd_warnf(const char *format, ...) {
         _cleanup_free_ char *p = NULL;
         va_list ap;

src/shared/daemon-util.h

@@ -21,6 +21,7 @@ static inline void notify_on_cleanup(const char **p) {
                 (void) sd_notify(false, *p);
 }
 
+int notify_remove_fd(const char *name);
 int notify_remove_fd_warn(const char *name);
 int notify_remove_fd_warnf(const char *format, ...) _printf_(1, 2);
 int close_and_notify_warn(int fd, const char *name);

src/udev/udev-config.c

@@ -557,9 +557,10 @@ int manager_serialize_config(Manager *manager) {
         if (r < 0)
                 return log_warning_errno(r, "Failed to finalize serialization file: %m");
 
+        /* This may fail on shutdown/reboot. Let's not warn louder. */
         r = notify_push_fd(fileno(f), "config-serialization");
         if (r < 0)
-                return log_warning_errno(r, "Failed to push serialization fd to service manager: %m");
+                return log_debug_errno(r, "Failed to push serialization fd to service manager: %m");
 
         log_debug("Serialized configurations.");
         return 0;

src/udev/udev-manager.c

@@ -1503,7 +1503,7 @@ int manager_main(Manager *manager) {
         /* We will start processing events in the loop below. Before starting processing, let's remove the
          * event serialization fd from the fdstore, to avoid retrieving the serialized events again in future
          * invocations. Otherwise, the serialized events may be processed multiple times. */
-        (void) notify_remove_fd_warn("event-serialization");
+        (void) notify_remove_fd("event-serialization");
 
         r = sd_event_loop(manager->event);
         if (r < 0)